Any interest in supporting Proas

[A8B]

Is there any interest in supporting Proas?

Brief history of this boat design http://harryproa.com/?p=1881

Proas do not, generally, tack or jybe. They shunt. please see http://harryproa.com/?p=1910

Currently no vendor plotter supports shunting.

There is an active community of personal Proa builders that are looking for a plotter solution.

Any thoughts?

[PaddyB]

What exactly is you want in a plotter? Opencpn with a gps should be fine shunting, magnetic compass could be 180 deg out half the time though.

[seandepagnier]

I do have interest to support proas in pypilot.

The thing is, it already works... The difference as mentioned is compass 180 degrees out half the time, but this won't stop pypilot. Now you need 2 rudders generally, so not sure if you have 2 actuators or what.

So perhaps a shunt function instead of tack. tacking isnt really working anyway, (but it will very soon) What else is different for proas in opencpn/pypilot?

[A8B]

I have asked sailors and builders from our community to contribute, as I am not sure I am the best to answer all these questions.

I guess they have to register and that seems like it might take a bit of time.

Thank you for your patience.

Here is a recent thread on the topic

https://groups.io/g/HarryProa/topic/83495350

If a shunt function is added, it could easily flip the compass. Even if that is just a display issue.

[PaddyB]

flipping wind & compass 180 deg should be easy enough in node red, though such a minority group might not be anything more than that..

[seandepagnier]

Should it use heel or gps for hints to determine which shunt you are on or is this manually entered?

a lot of the cheapest wind sensors like davis have 7 degree deadband This should be aimed to leeward and 90 degree offset added where wind is never supposed to come from as opposed to straight forward like other sailing boats.

[A8B]

Should it use heel or gps for hints to determine which shunt you are on or is this manually entered?

Probably no heel to check. The Proa is a very stable multihull. So gps?

But there are other things like lighting changes that we are thinking through. Like putting a tri light on each mast of the schooner rigged boat, and turning the forward one on and the aft off. Also need to switch the side lights.

Some have suggested it might be easier to flip a switch to inform all the systems of the new direction.

Perhaps it might not be needed if we can get smart enough software.

a lot of the cheapest wind sensors like davis have 7 degree deadband    This should be aimed to leeward and 90 degree offset added where wind is never supposed to come from as opposed to straight forward like other sailing boats.

Agreed.

Can the davis 7 be set up to report wirelessly?

Have you done any work with, or know who has done work with, ultrasonic water speed/direction sensors?

an example
https://www.airmar.com/productdescription.html?id=196

These parts are common enough in the automotive domain. Would be neat to hack together a cheap alternative.
Water speed, direction and temperature in one hard to clog sensor.

[seandepagnier]

yes, ultrasonic is very intersting but I am skeptical of the accuracy especially at low speeds as the time of flight is quite fast. You generally need two transducers. Now, if you could separate them by several meters the accuracy could get much higher.

In theory a paddle wheel style water speed sensor should work in both directions, but not sure all of them are able to tell you which direction they spin without 2 magnetic sensors.